perestroika

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[–] perestroika 2 points 1 year ago* (last edited 1 year ago)

To have conservatives firmly on board instead of rolling around the deck and causing damage, I propose calling it "global queering". /s

[–] perestroika 4 points 1 year ago* (last edited 1 year ago) (1 children)

A few more notes: carbon black is is not your ordinary chimney soot, but a different variety. It forms during incomplete combustion of some kinds.

It is quite conductive electrically and self-organizes into fractal tree-like structures inside cracks within drying cement. They predict that 45 cubic meters can store 10 KWh of energy - but large scale studies haven't been made yet.

I don't currently know what dielectric material they used between two castings of cement, but I imagine they used some type of plastic. It should be noted that you need a fair amount of carbon:

the “sweet spot” is around 10 percent carbon black in the mix

[–] perestroika 3 points 1 year ago* (last edited 1 year ago)

Long, informative, definitely worth a read - and depressing.

If natural climate fails to deliver water, and neigbours claw away what they can while it's upstream - this means either desalination, condensing water out of air (I would prefer if this technology was needed on Mars)... or just retreating from a place where nothing worthwhile can be done.

[–] perestroika 6 points 1 year ago* (last edited 1 year ago)

I'll try too.

Water can be split with electricity into hydrogen and oxygen atoms, which quickly combine into hydrogen and oxygen gas molecules.

This battery stores energy by using an acid environment to preserve the hydrogen atoms as single and electrically charged ions (weakly combining them with opposite-charge ions from an acid) and uses voltage to attract them into a carbon storage medium, where they de-ionize with the help of electrons from a wire and get deposited in porous carbon as single hydrogen atoms.

Meanwhile, oxygen is formed on the other electrode, far across a membrane. The oxygen cannot come across the membrane and combine with the hydrogen or carbon. Oxygen atoms react among themselves and form oxygen gas molecules.

When time comes to discharge, voltage across the terminals is removed and a load with resistance is installed. Hydrogen atoms stored in carbon give away their electrons, which flow across the wire (peforming work at the load) and ionize oxygen atoms on the other side. This creates a voltage gradient which attracts hydrogen ions to leave the carbon substrate and travel across the medium (acid conductor and membrane) to join with the oxygen ions and form water.

[–] perestroika 3 points 1 year ago* (last edited 1 year ago)

Thank you, the drawing is especially helpful. And apparently, the guys are running little fans off their prototype.

[–] perestroika 5 points 1 year ago* (last edited 1 year ago)

It seems to be a hydrogen fuel cell with an integrated hydrogen atom store made of carbon, capable of absorbing 1% of its own weight in hydrogen.

This seems a little, but a mass unit of hydrogen contains a lot of molecules, so a lot of chemical energy (it is the lightest element after all). For example, 1 kilogram of hydrogen is 12 cubic meters at room temperature, so 1 gram is 12 liters - enough to do a lot of work, if reacted right.

[–] perestroika 51 points 1 year ago* (last edited 1 year ago) (2 children)

This is such a puzzle, thank you. :)

I checked Sci-Hub - no matches for "proton battery", neither for "hydrogen flow battery".

Falling back on chemistry - I recalled that "dissolving a concentrated acid in water should be done with care". It is exothermic, water may suddenly boil and splash acid all over the careless chemist.

By definition, acids are substances that can easily give protons (hydrogen ions) to other chemicals. A classic reaction would be acid + base = salt + water (acid gives the H and base gives the OH, so we get H2O), the other components of the acid and base form the salt.

If there is only water on the other side, I thought "the reaction is acid giving protons to water". Which acid? How many protons? Those questions might determine the amount of power available. And of course - how to control the reaction and extract electrical power? Browsing Wikipedia, I came across two pages: protonation and deprotonation and a sample reaction with sulphuric acid, but found no reference to electricity production, though potential / voltage is obviously available when ions are being created and transfered.

Then, finally I found the RMIT press release, and understood that acid is not a central participant of this reaction:

https://www.rmit.edu.au/news/all-news/2018/mar/all-power-to-the-proton

Some pickings:

The working prototype proton battery uses a carbon electrode as a hydrogen store, coupled with a reversible fuel cell to produce electricity.

It’s the carbon electrode plus protons from water that give the proton battery it’s environmental, energy and potential economic edge, says lead researcher Professor John Andrews.

During charging, the carbon in the electrode bonds with protons generated by splitting water with the help of electrons from the power supply. The protons are released again and pass back through the reversible fuel cell to form water with oxygen from air to generate power. Unlike fossil fuels, the carbon does not burn or cause emissions in the process.

The researchers’ experiments showed that their small proton battery, with an active inside surface area of only 5.5 square centimetres (smaller than a 20 cent coin), was already able to store as much energy per unit mass as commercially-available lithium ion batteries. This was before the battery had been optimised.

“Future work will now focus on further improving performance and energy density through use of atomically-thin layered carbon-based materials such as graphene, with the target of a proton battery that is truly competitive with lithium ion batteries firmly in sight,” Andrews said.

There is a photo of the three scientists with a cell and multimeter, and the meter reads 1.1559 volts, so we know the cell voltage is low, but not impractically low. A link to a scientific article and a description of the cell follows:

"Technical feasibility of a proton battery with an activated carbon electrode"

The latest version combines a carbon electrode for solid-state storage of hydrogen with a reversible fuel cell to provide an integrated rechargeable unit.

During charging, protons produced by water splitting in a reversible fuel cell are conducted through the cell membrane and directly bond with the storage material with the aid of electrons supplied by the applied voltage, without forming hydrogen gas.

(this implies that overcharging results in hydrogen formation, like in lead acid batteries - the solution is to have it vented typically)

In electricity supply mode this process is reversed; hydrogen atoms are released from the storage and lose an electron to become protons once again. These protons then pass back through the cell membrane where they combine with oxygen and electrons from the external circuit to re-form water.

(this leads to the question of oxygen availability on the other side, and how to ensure it's adequate - gases are a nuisance due to their low density, but water can dissolve only so much oxygen, and this could limit the power output or storage capacity of the cell, however, if one built a flow battery, a redundantly large mass of water could be used to supply oxygen - but I'd really like to know if they used gaseous or dissolved oxygen)

Therefore, in the proton battery, many processes in the conventional hydrogen-based energy storage system that cause energy losses and irreversible entropy increases are omitted, such as hydrogen gas evolution and compression, and the splitting of molecular hydrogen into protons in fuel cell mode.

A summary of the scientific paper:

The experimental results reported here show that a small proton battery (active area 5.5 cm2) with a porous activated carbon electrode made from phenolic resin and 10 wt% PTFE binder was able to store in electrolysis (charge) mode very nearly 1 wt% hydrogen, and release on discharge 0.8 wt% in fuel cell (electricity supply) mode. A significant design innovation is the use of a small volume of liquid acid within the porous electrode to conduct protons (as hydronium) to and from the nafion membrane of the reversible cell. Hydrogen gas evolution during charging of the activated carbon electrode was found to be very low until a voltage of around 1.8 V was reached. Future work is being directed towards increasing current densities during charging and discharging, multiple cycle testing, and gaining an improved understanding of the reactions between hydronium and carbon surfaces.

So, the acid was not a reaction participant, but a proton conductor.

If anyone has a copy of the paper, please share - it seems like it would be interesting. :)

[–] perestroika 7 points 1 year ago (1 children)

Excellent article, thanks for sharing.

I hope they do find out what causes it to happen now, and to happen at this pace.

Countermeasures are the obvious ones, of course. People cannot prevent the oceans from doing their thing, but they can stop doing what they're doing to the atmosphere.

For those who want maps and graphs to describe the problem, this site offers a bunch.

[–] perestroika 4 points 1 year ago* (last edited 1 year ago)

I have tried polycarbonate, with miserable results. The clear silicone did not not adhere well, and thermal expansion ratios were in mismatch - the panel destroyed itself soon, interior components separated from the polycarbonate, the panel was mounted vertically and deformation started (tracks started curving downward).

Test thoroughly and if you have doubts about mechanical resilience, maybe use the panel horizontally.

Glass is a silicate, and may have the unique advantage of expansion ratios matching silicon wafers.

[–] perestroika 1 points 1 year ago* (last edited 1 year ago)

That's the rate when an infection establishes itself in blood. In a known outbreak (Royal Brompton Hospital), I recall that 9 patients out of 50 (18%) developed candidemia, but none of them died.

However, a study from India reports:

Among 1,400 ICU-acquired candidemia cases (overall incidence of 6.51 cases/1,000 ICU admission), 65.2 % were adult. Though the study confirmed the already known risk factors for candidemia, the acquisition occurred early after admission to ICU (median 8 days; interquartile range 4-15 days), even infecting patients with lower APACHE II score at admission (median 17.0; mean ± SD 17.2 ± 5.9; interquartile range 14-20). The important finding of the study was the vast spectrum of agents (31 Candida species) causing candidemia and a high rate of isolation of Candida tropicalis (41.6 %). Azole and multidrug resistance were seen in 11.8 and 1.9 % of isolates. Public sector hospitals reported a significantly higher presence of the relatively resistant C. auris (8.2 vs. 3.9 %; p = 0.008) and C. rugosa (5.6 vs. 1.5 %; p = 0.001). The 30-day crude and attributable mortality rates of candidemia patients were 44.7 and 19.6 %, respectively. Logistic regression analysis revealed significant independent predictors of mortality including admission to public sector hospital, APACHE II score at admission, underlying renal failure, central venous catheterization and steroid therapy.

Notes:

  • C. auris is observed together with other pathogens like C. rugosa and C. tropicalis, leading to the question of which of them is the killer, or whether co-infection is the killer

  • the mortality rate is given as a percent of people who developed candidemia (had Candida infections in their bloodstream), not as a percent of the total; upon hasty reading this can fool a person, and has fooled people before

  • the mortality rate is split into two variables: crude mortality (the patient is dead, the patient tests positive) and attributable mortality (the patient is dead, we can see how Candida killed the patient)

  • they found correlations which increased the risk; since they list "admission to a public sector hospital" among the factors, low standards of care in the Indian public healthcare system, or lack of experience in dealing with Candida (including wrong treatment protocols) may explain part of excess mortality

The study from Venezuela (a country afflicted with civil conflict and poverty) reports:

A total of 13 critically ill pediatric and 5 adult patients, with a median age of 26 days, were included. All were previously exposed to antibiotics and multiple invasive medical procedures. Clinical management included prompt catheter removal and antifungal therapy. Thirteen patients (72%) survived up to 30 days after onset of candidemia. AFLP fingerprinting of all C. auris isolates suggested a clonal outbreak. The isolates were considered resistant to azoles, but susceptible to anidulafungin and 50% of isolates exhibited amphotericin B MIC values of >1 μg/ml.

Unfortunately, the summary does not give adequate clues to understand the underlying conditions of the people (as I notice - mostly children). It mentions they were "critically ill", but doesn't mention if they were critically ill with Candida or before getting Candida. With such statistics as given in the summary - it is truly hard to evaluate the danger posed by a pathogen, because it's hard to isolate it from other factors. However, 30-day mortality was 28%, which is miserable.

My main conclusion seems to be: the first line of defense is having a hospital system that is ready to detect and deal with Candida. If this exists, many deaths can be avoided.

Of course, vaccination would be far preferable to combating it at a later stage.

[–] perestroika 1 points 1 year ago* (last edited 1 year ago)

Looks bad. I also suggest looking here for better context:

https://zacklabe.com/antarctic-sea-ice-extentconcentration/

(Zachary Labe is a climate scientist, Eliot Jacobson is a professor of mathematics)

My impression:

Ice extent is far below normal, 2023 is the worst year on recent record.

Ice volume has not responded dramatically yet (it has inertia) and there exists a year on recent record worse than 2023 - but it will respond soon enough.

Overall, I'm not sure if plotting a graph with standard deviations as the unit of measure is a good choice. It helps shake people up from sleep - yes. You typically look for standard deviations to determine if something is happening - and 6 deviations is considered solid proof. But to examine the quantity of ice, you measure square and cubic kilometers.

[–] perestroika 7 points 1 year ago* (last edited 1 year ago)

The Wikipedia article is perhaps more helpful than the news story.

Fungi are much closer to animals in evolutionary terms than bacteria. Many substances which effectively kill fungi are harmful to animals, including humans. Antibacterial antibiotics are mostly useless. There exist antifungal antibiotics, but their selection is limited. Vaccination is possible, but not yet feasible in people. A mouse has been successfully vaccinated against Candida auris and gained some protection.

Fungal diseases are generally slower compared to viral (very fast) and bacterial (fast) diseases, but harder to wipe out.

This fungus is generally a threat in hospitals, where people with compromised immune systems and open wounds may be encountered. A description of a Candida outbreak in a medical setting can be found here. It broke out in the intensive care unit of a London hospital. Many patients had wounds, catheters or intravenous lines. They resorted to isolating every patient, disinfecting rooms with agressive substances, using plentiful chrorhexidine to prevent infection via wounds and lines, and antifungals to treat patients.

Nobody died at the Royal Brompton Hospital, but the mess was severe. Candidasis of the blood (typically after entry through a wound) has a high level of mortality. Whether it is a case fatality ratio or infection fatality ratio - no idea. With new diseases, one typically learns the CFR first and IFR much later, except in hospitals where you can test every person.

Next year, the US CDC described it as a "catastrophic threat". Antifungals that target Candida with less side effects, and a vaccine against it, are highly sought after. I trust they will be found, but not soon - this is not COVID, it spreads slowly, so everyone isn't running (yet) to put a lid on it.

The hypothesis about how it crossed to humans, is summarized by this picture. Wetlands -> thermotolerance -> birds -> agricultural setting -> humans -> hospital setting. I'm not sure if this guess is correct, but it has explanatory value.

Apparently it was capable of crossing species barriers anyway, because it's a generic sort of decomposer fungus - it needs nothing highly specific, and breaks down a variety of biomolecules for food. What is notable: it gained resistance to antifungals before entering people. Probably through agricultural use.

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